Fred R. Volkmar, Brian Reichow and James C. McPartland (eds.)Adolescents and Adults with Autism Spectrum Disorders201410.1007/978-1-4939-0506-5_12
© Springer Science+Business Media New York 2014
12. Medical and Health Problems in Adults with High-Functioning Autism and Asperger Syndrome
(1)
The Redpath Centre, Toronto, ON, Canada
(2)
The Redpath Centre and University of Toronto, Toronto, ON, Canada
Abstract
Adults on the autism spectrum experience a wide range of medical and health problems—some at a higher prevalence compared with the general population. Although these problems can significantly affect quality of life, information on medical comorbidities for this group is sparse, and general knowledge of disorders associated with autism spectrum disorder (ASD) in community-based medical settings is lacking. In this chapter, we review medical and health problems experienced by adults with ASD. We begin this discussion by examining possible risk factors associated with health problems in this group, in addition to the current literature on prevalence rates of specific disorders. The focus of this chapter is on those who have historically been identified with “high-functioning autism” or Asperger syndrome.
Adults on the autism spectrum experience a wide range of medical and health problems—some at a higher prevalence compared with the general population. Although these problems can significantly affect quality of life, information on medical comorbidities for this group is sparse, and general knowledge of disorders associated with autism spectrum disorder (ASD) in community-based medical settings is lacking. In this chapter, we review medical and health problems experienced by adults with ASD. We begin this discussion by examining possible risk factors associated with health problems in this group, in addition to the current literature on prevalence rates of specific disorders.
The focus of this chapter is on those who have historically been identified with “high-functioning autism” or Asperger syndrome (AS). This cluster of individuals has relatively good language development and near-average to above-average intelligence. Their primary challenge is social: they have problems understanding social rules and expectations, difficulties conversing in a reciprocal manner, and may experience high social anxiety—sometimes leading to social avoidance. They exhibit characteristics such as excessive interests in certain subjects, strict adherence to routines, hypo- or hypersensitivities, or obsessive and/or compulsive features. Because of the general lack of professional knowledge about these adults and inadequate access to services, many are diagnosed in adulthood (Stoddart, Burke, & King, 2012). For a community-based sample in Canada, 48 % of individuals with “high-functioning autism” and AS were not diagnosed until they were 21 years or older (Stoddart et al., 2013).
Empirical literature reports the co-occurrence of a number of classes of disorders that are associated with ASD including neurological, digestive and gastrointestinal, metabolic, autoimmune, and genetic disorders. Some diseases seem to occur within families, in the absence of a known genetic vulnerability. Others, such as epilepsy, present with higher frequency in those with ASD and comorbid intellectual disabilities. Another group of conditions appear to be random and may be, in part, attributable to other ASD-related features such as concurrent idiosyncratic sensory processing (e.g., heightened sensitivity to pain) and mental health struggles (e.g., bouts of diarrhea related to anxiety).
Health Risk Factors in Adults with ASD
What am I to do? To have anything like a reasonable quality of life, my life is abominably high-maintenance. I can’t find a medical doctor who is willing to work with me without the drugs that I get all the side-effects for, unpredictable intended effects, and wild-card effects that don’t show up in the literature at all. I don’t know how to live in this world, never mind participate in it.
As reflected in this quote from a woman with ASD, research and professional education on medical and health problems experienced by this patient group have been largely been neglected. We found a dearth of studies addressing the health needs of those on the milder end of the spectrum compared with an increasing body of literature for this group related to social, emotional, psychiatric, communication, educational, and employment needs. More important, members of the multidisciplinary team needed to support adults with ASD are left with few guidelines as to how to recognize and address these medical and health concerns in their practices.
Although it is not possible to determine if ASD itself gives rise to increased mortality in this group, the specter has been raised and examined in numerous reports. Mortality studies in ASD provide us with some clues about significant medical concerns for this group and underscores the necessity of recognition and treatment. A recent population-based mortality study in Sweden found an almost sixfold increased mortality rate among individuals with ASD, as compared to the general population. Of nine deaths reported, four were related to “sudden unexpected death in epilepsy,” two to “cerebral infection/malignancy,” two to accident, and one to cardiac insufficiency (in an individual with Trisomy 13; Gillberg, Billstedt, Sundh, & Gillberg, 2010). In a California study examining the deaths of 202 individuals, major causes of death included circulatory problems (n = 22), cancer (n = 21), seizures (n = 15), congenital abnormalities (n = 16), drowning and suffocation (n = 18), respiratory problems (n = 13), digestive (n = 13), and diseases of the sensory and nervous systems (n = 10). The standardized mortality ratio (SMR) for those with no or mild mental retardation was elevated for seizures (22.6) and nervous and sensory diseases (4.8). Overall, higher rates of mortality occurred in those with severe intellectual disability, although individuals with all levels of IQ were affected with an SMR of 2.4 (Shavelle, Strauss, & Pickett, 2001). Finally, a review of a clinical sample of 341 in Denmark followed for 24 years found the average age at the death of 12 individuals was 22 years; 9 of the 12 individuals had medical comorbidities. Both severe retardation and normal intelligence were associated with high risk of death (Iasger, Mouridsen, & Rich, 1999).
Below, we briefly review variables that may be risk factors for this cohort, based on our clinical experience and review of the existing research. The social determinants of health (such as race, gender, education, and income) are relevant for the general population and for individuals with disabilities (WHO, 2011a, 2011b). Discussion of social determinants is beyond the scope of this chapter; however, we believe they are also highly applicable to adults with ASD. Empirical exploration of the determinants of health is critically needed for this patient cohort, both in developed and developing countries. We highlight only the most significant risk factors relating to health and wellness here: aging, medication use, features characteristic of ASD, genetics, and poor cross-systems knowledge exchange.
Risks Associated with Aging
Until recently, the research examining health issues in those with ASD has focused on children. Some medical disorders may not present until adulthood, or perhaps have been present since childhood but not diagnosed until adulthood. It has been suggested that adolescence is a period when an individual with an ASD is at increased risk for developing health problems such as seizures and gastrointestinal problems (Kring, Greenberg, & Mailick Seltzer, 2010).
The risks associated with individuals with aging and milder ASD is a relatively unexplored area (Povey, Mills, & Gomez de la Cuesta, 2011). We are identifying many individuals with ASD in later life (50 years and over) as are others around the world (James, Mukaetova-Ladinska, Reichelt, Briel, & Scully, 2006). Some of these are older family members of those previously diagnosed with ASD (Ritvo, Ritvo, Freeman, & Mason-Brothers, 1994).
Furthermore, services and supports for adults with ASD are often lacking, and intervention, especially in “milder” ASD, may occur in later life only. Increasing attention is also being given to disease presentation and prevention in older individuals with developmental disabilities generally, and in older adults with ASD specifically (Povey et al., 2011; Stoddart, 2005, 2006), as more individuals with developmental disabilities are living longer and reaching older age. A working knowledge of ASD has yet to be widely disseminated into the sector caring for aging individuals and vice versa, which leads to systemic and practice-related vulnerabilities for older adults living with ASD.
Risks Associated with Medication Use
Medication use is common, and often long term, in individuals with ASD. In our recent study of 480 youth and adults with ASD, we found that there was a high rate of medication use, despite this being a relatively young sample. They ranged in age from 16 to 66 years, with an average of 29.11 years—80.6 % were 40 years or younger. The mean number of medications used per individual in this study was 1.65 (SD = 1.76) with 63.1 % taking at least one medication; some were taking as many as six or seven. “Medication use was correlated with age (r = 0.220; p < 0.001), number of physical illnesses (r = 0.348; p < 0.001), and number of psychological diagnoses (r = 0.283; p < 0.01)” (Stoddart et al., 2013, p. 25). Multiple medication use may be an artefact of poor physician monitoring, lack of awareness of multiple prescribers, poor patient follow-up, unmanaged behavioral problems, and unavailability of alternative treatment approaches.
The long-term effects of medication are an ongoing concern of prescribers and patients. Second generation antipsychotic medications are increasingly being used with children and adolescents presenting with psychiatric and behavioral difficulties, and there is some evidence that this may result in metabolic and endocrine disturbances (De Hert, Dobbelaere, Sheridan, Cohen, & Correll, 2011). Some adults may understandably be alarmed by the side effects of medications listed on patient information sheets or the Internet physiologically sensitive to, or hypervigilant about adverse reactions. A history of idiosyncratic or even paradoxical responses to medications may precede patient concerns (Sloman, 2005; Stoddart et al., 2012; Towbin, 2003).
Many individuals on the spectrum and their families would prefer to use naturally occurring substances or Complementary and Alternative Medicines (CAMs). Two examples from our practice are the use of melatonin for improving sleep and marijuana/tetrahydrocannabinol (THC) to treat anxiety, insomnia, or pain. Other CAMs which have been noted in the literature include multivitamins, gluten-casein free diet, vitamin B6, and magnesium; reviews of efficacy and safety are just emerging (Akins, Angkustsiri, & Hansen, 2010; Anagnostou & Hansen, 2011). In their review of medical treatment and CAMs, Anagnostou and Hansen note “…healthcare professionals need strategies and tools to help families negotiate the many available CAM treatments and make decisions based on current safety and efficacy” (p. 623).
Risk Associated with Sensory, Executive Function, Mental Health, and Social Problems
Many of our patients are at risk of inadequate or improper medical care because of features associated with ASD. For example, sensory processing concerns are not generally thought of in relation to medical disorders. However, hypo- or hypersensitivity can play a role in the detection and retreatment of health concerns. We recently learned of a woman with high-functioning autism that did not report on pain in her abdomen as early as others might have. Unfortunately, she was diagnosed with cancer and before treatment could begin, succumbed to the illness. Some authors have suggested that high levels of sensitivity may be related to the unusual way those with chronic fatigue syndrome (CFS) and fibromyalgia process physical responses.
Second, clinical experience tells us that despite having average or above-average intelligence, individuals with ASD still struggle with planning, initiation, problem solving, and sequencing life’s demands. Many have difficulty finding and using services and supports (Stoddart et al., 2012, 2013). In higher-functioning individuals with average to above-average IQs, there is often a “cloak of competence” (Egerton, Bollinger, & Herr, 1984) or an assumption of competence when it comes to these basic life skills. Adults who are highly accomplished in their work may have basic problems with organization at home, or for tasks which are of less interest. Not surprisingly, these executive functioning problems carry over into medical and health care. Simply finding and arriving at a specialist clinic on time can be a challenge. In an overburdened medical system, the patient who misses a specialist appointment is either dropped from the referral list or put back at the bottom of a long waiting list for nonlife-threatening illnesses.
Third, social interaction also affects contact and interactions with medical personnel. Individuals with ASD may be reluctant to raise “private” medical issues with their family doctors such as birth control, irregular menses, or bowel problems. one young man we saw in our clinic was experiencing significant genital discomfort, which resulted in him losing his employment, but he refused to raise this with his doctor, or subject himself to a medical exam. As well, our patients appear socially odd or awkward, thereby reducing their credibility when reporting symptoms.
Fourth, we know that anxiety and depression are commonly seen in individuals with ASD. These symptoms may contribute to difficulties accessing medical services and supports, especially in cases of extreme social anxiety, requirement of meeting strangers, making appointments by telephone, or sitting in a crowded waiting room with (usually ill) strangers. Patients with a known history of anxiety disorders, (traits of) obsessive compulsive disorder, and hypochondriasis may also be viewed as unreliable and anxious-prone informants in a medical examination.
Risks Associated with Genetic Vulnerability
There is a body of literature suggesting that some of the disorders seen in those with ASD may have a familial link, having been present in the mother during pregnancy, having a pattern of occurrence in families, as well as being identified in childhood (Gillberg, Gillberg, & Kopp, 1992; Hoshiko, Grether, Windham, Smith, & Fessel, 2011). It is well established that ASD presents more often in families where an ASD has already been identified, and characteristics of AS/ASD are often noted in other family members (Burke, 2005). It is also reported that mental disorders such as mood disorders, which are present in family members, may also present in a child with an ASD, suggesting possible heritability (Attwood, 2007).
While we have come to view AS and autism as part of the same family of disorders, and in North America are moving to a diagnostic system that does not distinguish between the disorders beyond severity, many clinicians and researchers have cited features which suggest the disorders are distinct. Genetic research examining gene regions within families indicate occurrence of both AS/ASD-shared as well as AS distinct regions (Salyakina et al., 2010). Recent findings from genome research which looked at single-nucleotide polymorphism (SNP) of five mental disorders suggest associations across the disorders. Those investigated were ASD, ADHD, bipolar disorder, major depressive disorder, and schizophrenia (Cross-Disorder Group of the Psychiatric Genomics Consortium, 2013).
The above research indicates transmission of features of ASD may be specific to an ASD diagnosis, may cross within the ASD family, or may cross other mental or neurologically based disorders. It would seem reasonable, then, that medical and health issues may also be part of the presentation of an ASD, as are seen in many other syndromes, and that these may also be genetically transmitted. It would therefore be important for families to gather information, not only related to features of ASD within family members but also related to mental and physical health concerns. Further, medical practitioners should ensure symptoms of health disorders are thoroughly investigated. Interestingly, the National Autistic Society in the UK has introduced a health family tool to assess not only an individual’s health but also their family’s health history which will allow knowledge of diseases, not necessarily ASD-related or more common in ASD, but that run in families such as diabetes, heart disease, and cancer (Povey et al., 2011).
Risk Associated with Poorly Informed Medical Systems
The knowledge of healthcare providers in the community is limited when it comes to knowledge of higher incidence disorders in ASD. Chronic disorders from childhood will continue into adult years, even if they are controlled through medication or other forms of treatment. The experiences of children and youth with ASD and their families are surprisingly poor, even in specialist pediatric hospitals (Muskat et al., 2012). The carry-over of these poor or even traumatizing experiences is often voiced by older youth and adults long after these episodes.
In our practices, many adults, without the benefit of an ASD diagnosis, were previously diagnosed with a series of seemingly unrelated medical problems. When they are finally diagnosed with an ASD in later life they appear “relieved” to discover that many of the medical issues that they have struggled with their entire lives are common for individuals with ASD. These include allergies, dietary restrictions, gastrointestinal issues, and hormonal problems. In some cases, knowing this, they can access medical practitioners with experience in ASD, or benefit from information that they access on their own. We review many of these higher risk clusters of disorders below.
In practice, we routinely ask about co-occurring medical issues in both diagnostic and treatment appointments and ensure that they are being addressed (Stoddart, Burke, & King, 2012). Although we lack sophistication in our current understanding of health issues and adult ASD, in the future we can theoretically use our knowledge of high prevalence medical issues to assist in the diagnostic process, and in implementing more focused treatments for these comorbidities.
Individuals with ASD and their families have reported difficulty obtaining appropriate health care or having their symptoms resolved (Stoddart et al., 2013). Graetz (2010) has suggested that there are not enough medical practitioners who understood the needs of their clients on the spectrum. Barnhill (2007) discussed physical health of adults with AS, indicating some may have chronic aches, pain, and fatigue which impact on other areas of life. She noted her own son had such experiences, and had difficulties identifying his complaints, making it challenging for his physician to offer appropriate treatment.
Further, in the absence of centralized medical management, electronic records exchange, and largely community-based decentralized services for adults with ASD, individuals are challenged to understand what knowledge care providers require, may make assumptions that general practitioners or specialists are knowledgeable about particular issues, or that they are able to follow through.
In a comparative study of individuals on the autism spectrum and those who were unaffected, those on the spectrum reported significantly greater unmet health needs, less patient-provider communication, and less resolution of symptoms of chronic health problems. Participants in the survey were primarily those with a diagnosis of AS (Nicolaidis et al., 2013). Through a Connecticut study, physicians were asked about their experiences with adults on the autism spectrum; 40 % of the responding physicians indicated they did see adults with ASD. Most patients did not live independently and did not, or could not, follow medical recommendations on their own. Of the responding physicians, only 36 % had received training related to serving adults with ASD; half of the respondents indicated they would like training (Bruder, Kerins, Mazzarella, Sims, & Stein, 2012).
Prevalence Research and Methodological Considerations
It is important that we understand the likelihood of co-occurrence of certain medical and health issues in those with ASD as well as the impact these disorders have on the individual. This will allow physicians to be more cognizant of potential investigations that may be necessary as well as ensuring there are appropriate interventions available. It will also allow individuals and their families to ensure they seek appropriate care when certain symptoms are present. The medical and health issues we review reflect recent studies reporting the presence of these disorders in adults on the spectrum. However, in discussing the specific disorders, some of the research may primarily have been carried out with children or youth.
Often studies reviewed combine adults across functioning levels, with or without intellectual disability, or do not specify functioning levels, so that it is not clear what factors might actually be predictors of health or medical disorders in those on the spectrum. Other factors such as age, access to healthcare, age of diagnosis, and other risk factors articulated in the last section are not necessarily noted. Many have previously discussed the wide heterogeneity of ASD (Stoddart et al., 2012; Willemsen-Swinkels & Buitelaar, 2002). The possibly wider range of presentation and functioning in adulthood has important implications for research and service provision (Stoddart et al., 2013). Shattuck and colleagues argue: “Although few studies have analyzed the implications of the heterogeneity of both abilities and challenges exhibited by people on the autism spectrum for service provision, such heterogeneity is vast [and] has significant implications for service needs” (Shattuck et al., 2012, p. 289) and for our purposes, healthcare and medical management.
A number of disorders, including those which are genetic, metabolic, as well as other developmental syndromes, have been found to exist in people who exhibit more severe symptoms of autism (Miles, McCathern, Stichter, & Shinawi, 2010). Some of these include Fragile X, tuberous sclerosis, neurofibromatosis, hypo-melanosis of Ito and Moebius syndrome, phenylketonuria, adrenylosuccinate lyase deficiency, creatine deficiency, Smith-Lemli-Opitz syndrome, Angelman syndrome, and Landau-Kleffner syndrome (Gillberg, 1992; Miles et al., 2010).
Gillberg and Ehlers (1998) suggest that fewer than 15 % of those on the milder end of the spectrum will present with comorbid medical conditions. Those most likely to occur include fragile X, neurofibromatosis, and tuberous sclerosis. In 2000, Gillberg and Billstedt proposed the following prevalence rates of disorders concurrent with an ASD: epilepsy (30 %), anorexia nervosa (28 %), tuberous sclerosis (2–9 %), fragile X syndrome (2–10 %), and Thalidomide syndrome (4 %).
A recent large-scale review was conducted over four hospitals in the USA, including one pediatric setting (Kohane et al., 2012). Records of 14,000 individuals with ASD under the age of 35 were studied and the prevalence of comorbidities examined. Coexisting disorders in those under and over the age of 18 years were also compared. Among the identified comorbid physical health issues in children and young adults with ASD were: epilepsy (19.4 %), bowel disorders (11.7 %—excluding inflammatory bowel disease or IBD), CNS anomalies (12.4 %), autoimmune disorders (0.7 %—excluding IBD and Type 1 diabetes), diabetes mellitus Type 1 (0.8 %), IBD (0.8 %), and sleep disorders (1.1 %). When compared to prevalence of these disorders in the general population, all but autoimmune disorders was found to be greater. When age was examined, those over age 18 had a higher incidence of diabetes mellitus Type 1 and IBD, while occurrence of the other noted disorders did not vary. This study also confirmed previous research indicating presence of “single-gene” disorders associated with ASD, specifically fragile X syndrome, tuberous sclerosis, Down syndrome, and muscular dystrophy. The authors noted that occurrence of each individual disorder was at a low prevalence rate, although collectively, they might exceed 20 %.
Other research examined records from a national insurance database in Taiwan over a 14-year period and identified a higher incidence of allergic and autoimmune disorders in those with ASD than those found in a matched control group (Chen et al., 2013). Among the specific disorders occurring at an increased level were asthma, dermatitis, urticaria, allergic rhinitis, and Type 1 diabetes. A trend was found for concurrent ASD and Crohn’s disease. The sample included individuals across functioning levels.
In an American study, individuals with ASD ranging in age from 10 to 53 (Mean = 22) were followed over a 5-year period. Over 80 % of the parents rated their child’s health as good or excellent. Researchers found the most common health problems reported were difficulty sleeping (70 %), gastrointestinal complaints (58 %), breathing (asthma/allergies) problems (32 %), and seizure disorder (25 %). Other issues included problems with feet, teeth, high cholesterol, and migraine headaches. Medications were prescribed for anxiety, depression, seizures, behavior, breathing problems, gastrointestinal difficulties, sleep, hormonal issues, attentional issues, and skin problems (Seltzer & Wyngaarden Kraus, undated).
In Canada, Mousseau, Ludkin, Szatmari, and Bryson (2006) examined the quality of life of 19 “high-functioning” (i.e., IQ > 70) men with ASD with an average age of 30.8 years. The number of times per year the participants contacted healthcare professionals ranged from 4 to 67, with an average of 24. Body Mass Index was calculated with an average of 28.21 (i.e., average “overweight”). In another study of individuals with AS (Balfe & Tantum, 2010), reports of physical complaints included vision problems (24 %), hearing problems (24 %), involuntary movements (36 %), genetic problems (16 %), and neurological problems (16 %): 54 % of individuals took medication.
In our early study of adults (20+) with ASD, accessing services in a developmental service agency, 100 clinical files were reviewed (Stoddart, Burke, & Temple, 2002). In total, 32 (32 %) had a chronic medical issue including epilepsy (n = 9), cerebral palsy (n = 5), fragile X syndrome (n = 5), hearing/vision impairment (n = 4), head trauma (n = 2), and neuroleptic malignant syndrome (n = 2). Individual cases were identified with diabetes, asthma, hydrocephalus, thyroid disorder, ulcerative colitis, organic brain disorder, physical mobility problems, and temporal lobe dysgenesis.
In our recent study of 480 youth (16+) and adults with ASD in the community (Stoddart et al., 2013), we asked respondents to list up to three medical or health conditions. Approximately half of the sample were diagnosed with “high-functioning autism” or AS. A total of 296 conditions were named by respondents, and we grouped these into categories. In total, 176 (36.7 %) respondents identified at least one medical or health condition. Of the entire sample, 10.62 % reported brain and spinal cord disorders (e.g., epilepsy, brain injury), 9.79 % reported digestive system disorders (gastroesophageal reflux disease [GERD], irritable bowel syndrome [IBS], Crohn’s), and 9.38 % noted lung and respiratory disorders. Hormonal and metabolic disorders and musculoskeletal disorders were each reported in 6.46 % of the sample. Sleep disorders occurred in 2.92 %; 2.50 % indicated they experienced skin disorders and weight disorders. “There was no relationship between numbers of illness reported for each person and diagnosis or gender. However, there was a weak but significant correlation between number of illnesses and age (r = 0.250; p < 0.01)” (p. 24).
Genetic Disorders
There is increasing evidence that ASD has a genetic etiology, which may be influenced by environmental factors. Genetic testing is not always carried out with those diagnosed with an ASD, in our experience. However, it is reported that 5–9 % of those with an ASD has an identified chromosomal abnormality, and a vast number of chromosomes have been identified in case studies (Spence, Sharifi, & Wiznitzer, 2004).
Early evidence and interest in genetics came from twin studies, from studies showing the reoccurrence of ASD within families, and from case reports of coexistence of ASD with other genetic disorders. The higher incidence of ASD in males suggests a relationship to sex chromosomes. These factors have led to broad spread genome research (Klauck, 2006). While initially researchers believed one or two genes would be identified as causative factors in ASD, recent research suggests that “several hundreds of loci are likely to contribute to the complex genetic heterogeneity of this group of disorders” (Schaaf & Zoghbi, 2011, p. 806). This would seem to explain the great variety in presentation of those on the spectrum, as well as the large number of disorders that share features with ASD. While the genetic research will not be reviewed further in this chapter, some of the specific disorders will be discussed as will the medical concerns that are consequences of such disorders.
Fragile X Syndrome
Fragile X (FrX) occurs at a rate of 1:3,200–4,000 males and 1:6,000 females (Sherman, 2002) and results from mutation of the FMR1 gene on the X chromosome, preventing the gene from producing adequate FMR protein (FMRP; Denmark, 2002; Garber, Visootsak, & Warren, 2008; NICHD, 2003). As it is carried on the X chromosome, affected females show less severe symptom because they typically have one unaffected X chromosome (NICHD, 2003). The gene can be passed on without presentation of symptoms, resulting in some families being unaware that they carry the disorder. Those with FrX exhibit behavioral difficulties, learning challenges, and associated mental health problems, in addition to physical health characteristics. Physical features and health characteristics include a high palate, prominent jaw, long face, course features, large ears, increased head circumference, poor muscle tone, orthopedic problems, heart murmur, seizures, ear infections, vision problems, gastroesophageal reflux, and epilepsy (Garber et al., 2008; NICHD, 2003; Roberts & Kagan-Kushnir, 2005).
FrX has been associated with ASD (Denmark, 2002). Some have estimated that 30 % of those diagnosed with FrX have a concurrent diagnosis of ASD (Holden & Liu, 2005). While most of the professional literature examines the relationship between FrX and more severe subtypes of ASD, there is some suggestion of AS occurring with X chromosome atypicalities (Searcy, Burd, Kerbeshian, Stenehjem, & Franceschini, 2000), and we have observed this in practice.
Neurofibromatosis
Neurofibromatosis (NF1), also known as von Recklinghausen’s disorder, is caused by mutations on the 17th chromosome (17q11.2). The gene involved in NF1 regulates neurofibromin, a protein believed to suppress the development of tumors. In NF1, typically benign tumors develop in the central nervous system as well as other parts of the body, and abnormalities in skin pigmentation occur. Additional features may include increased head circumference, learning challenges, hyperactivity, seizures, and skeletal problems such as scoliosis (Mouridsen & Sorensen, 1995; Williams & Hersch, 1998). Williams and Hersch (1998) estimate that 70 % of those with NF1 will have a neurodevelopmental disorder, including learning disability, ADHD, and ASD. Dodd (2005) proposed in those who have AS, there is a slight increase in occurrence of neurofibromatosis compared to the general population.
Duchenne’s Muscular Dystrophy
Duchenne’s muscular dystrophy (DMD) is an X-linked disorder in which a gene mutation reduces the production of dystrophin, a protein providing stabilization of skeletal muscles. Dystrophin is typically found in the central nervous system. In males who have DMD, concurrent diagnoses of ADHD, ASD, Dyslexia, and OCD have been reported (Hendriksen & Vles, 2008). Poysky (2007) suggests the incidence of DMD in those with ASD is higher than in the general population.
Tuberous Sclerosis Complex
Tuberous sclerosis complex (TSC) is an inherited disorder in which a gene mutation reduces the availability of proteins that act to suppress tumors. The tumors contain overgrowth of nerves or connective tissue. Individuals with TSC have skin-related symptoms, such as light patches and growths. The impact of the resulting tubers is dependent on where the tubers develop. For some, growths develop on the kidney, eye, heart, or lung (Yates, 2006). Cortical tubers are related to epilepsy. Cortical tubers that grow in the temporal lobe appear to be present in individuals with ASD (Bolton, Park, Higgins, Griffiths, & Pickles, 2002). Behaviorally, individuals with TSC are prone to hyperactivity and sleep disturbance (Mahoney, 2002). While less than 4 % of individuals who have autism are diagnosed with TSC, as many as 50 % of individuals with TSC present with features of an ASD (Wiznitzer, 2004). Depending on the degree of impairment, this may include those with AS or milder forms of ASD.
Neurological Disorders
ASD is a neurodevelopmental disorder. Despite the inherent implication of this for brain function in ASD, there are additional neurological conditions which appear to coexist with ASD. The most commonly discussed are seizure disorders/epilepsy, and tic disorders, including Tourette syndrome. Some with ASD also report migraine headaches. Genetic disorders noted above may also have neurological implications.
Epilepsy/Seizure Disorders
Early research of those with autism identified the co-occurrence of epilepsy, and estimates suggest that 40 % of those with an ASD will develop epilepsy (Taylor, Neville, & Cross, 1999). While little research has occurred in those with epilepsy who are on the milder end of the autism spectrum, such as those with AS, Berney (2004) estimates the risk to be lower for those with AS than autism. He estimates 5–10 % in AS, with a later onset.
A review of the literature, revealed single case studies in which individuals presented with comorbid epilepsy and AS (Burgoine & Wing, 1983; Jones & Kerwin, 1990; Warwick, Griffith, Reyes, Legesse, & Evans, 2007). In a study of individuals with ASD being evaluated as candidates for epilepsy surgery, eight of the 19 had AS (Taylor et al., 1999). In a review of 100 cases of males with AS, Cederlund and Gillberg (2004) identified clinical epilepsy in four, with an additional 20 showing atypical EEGs.
An investigation of the relationships between hypothalamic hamartoma (HH) and psychiatric disorders was conducted by Ali, Moriarity, Mullatti, and David (2006). The authors note that HH has previously been identified as a cause of seizures with associated behavioral difficulties including aggressive behavior: “it is the HH that is the source of the seizures, and it is considered to be intrinsically epileptogenic” (p. 112). Ten patients were reviewed, all adults without cognitive impairments. Of these, five individuals were identified with feature of AS.
Tics and Tourette Disorder
Tourette disorder (TD) is a neurological disorder in which an individual exhibits motor and vocal tics or involuntary movements/sounds (Jankovic, 2001). The incidence of TD is higher in males than females, and onset occurs before age 18, with typical onset between the ages of 3 and 8 years. TD may present concurrent with other disorders such as ADHD and OCD.
An association between ASD and tic disorders, including TD, has been established in the literature over the past three decades (Baron-Cohen, Mortimore, Moriarty, Izaguirre, & Robertson, 1999; Epstein & Salzman-Benaiah, 2005; Kerbeshian & Burd, 1996; Marriage, Miles, Stokes, & Davey, 1993; Ringman & Jankovic, 2000; Sverd, 1991). Epstein and Salzman-Benaiah (2005) emphasize the considerable overlap of symptoms of AS and TS. Baron-Cohen et al. (1999) reported the occurrence of tic disorders in 6–8 % of their ASD sample. Freeman et al. (2000) reported a prevalence of 4.5 % in an ASD sample. In a review of 60 women on the milder end of the autism spectrum (Burke, Stoddart, & Abdelsayed, 2012), 8 % identified themselves with a diagnosis of TD.
Hormonal and Metabolic Disorders
There are many studies in the research literature which suggest a familial presence of metabolic or autoimmune disorders that may be related to the occurrence of an ASD in that family. It is purported that presence of metabolic conditions during pregnancy, such as diabetes, may increase the possibility of the child having a neurodevelopmental disorder, including ASD (Krakowiak et al., 2012). Adams et al. (2011) suggest that concurrence of metabolic disorders with neurodevelopmental disorders such as ADHD, intellectual disabilities, and learning disorders, has received increasing attention. They propose that metabolic and nutritional concerns are also relevant for those with ASD. Metabolic disorders are reported in the literature in those with ASD, although Spence et al. (2004) suggest the incidence is likely less than 5 %. Increasingly however, studies of health issues in those with ASD contain reports of hormonal and metabolic disorders (Seltzer & Wyngaarden Kraus, undated; Stoddart et al., 2013), suggesting a need to continue to examine this relationship.
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